The present invention relates to an insertion needle for insertion into a body cavity, such as for TVT (Tension-free Vaginal Tape) or TOT (Trans Obturator Tape) surgery that treats female urinary incontinence, and TVM (Tension-free Vaginal Mesh) surgery for pelvic organ prolapse.
The majority of female urinary incontinence is stress urinary incontinence. Females with stress urinary incontinence experience urinary incontinence during normal daily activities or movement, such as laughing, coughing, sneezing, or normal exercise.
Stress urinary incontinence is caused by a functional defect of the tissue or ligaments connecting to the urethra and pelvic bone; common factors for this include repetitive strain on the muscles in the pelvis, childbirth, loss of muscle tension in the pelvis, and a loss of female hormones. As a surgical treatment for stress urinary incontinence, TVT (Tension-free Vaginal Tape) surgery is common, and provides U-shaped reinforcement using tape made from polypropylene fiber, imagining the ligament passing through both sides of the pelvic bone and under the urethra, which is called the pelvic urethra ligament; in order to deliver the tape, a shaft, which has two comparatively thick, sharpened tips, must be used to pass through the vagina to reach the abdomen, and when inserting this shaft, the procedure is performed by way of groping, leading to a risk of damaging the structures inside the pelvis, such as the bladder, blood vessels, muscles, or nerves. Furthermore, to prevent this damage, visualization must be repeated by way of a cystoscope, and there is a disadvantage that a long time is required for surgery.
Various proposals have been made as countermeasures for this problem, but a fundamental means for solving the problem has yet to appear (see JP-2004-509685-A, for example).
Thus, in addition to the current TVT surgery described above, TOT (Trans Obturator Tape) surgery has been proposed as a new surgical method. This surgical method comprises the following steps.
(1) After performing anesthesia, a pair of right and left incisions is made in the skin at the obturator foramina and in the anterior vaginal wall. (A subcutaneous tunnel, of a size such as to allow a finger to be inserted, is created in the anterior vaginal wall.)
(2) A specialized insertion needle is inserted from the obturator foramen and comes out the anterior vaginal wall passing the back of the pubic bone. (At this time, a finger is inserted in the subcutaneous tunnel so as to guide the insertion needle.)
(3) After guiding the insertion needle from the anterior vaginal wall to outside the vagina, a tape is applied to a groove in the tip of the insertion needle, the insertion needle is extracted to outside of the skin, and the tape is drawn from the obturator foramen.
(4) The above operation is performed on the other obturator foramen side, and the tape is likewise drawn.
(5) After finely adjusting the tension of the tape drawn from the obturator foramina, the surgery is completed by suturing the skin and vagina.
Note that the above surgical method describes a method of pulling a needle from the obturator foramen to the vagina (outside in), but conversely a method of pulling from the vagina to the obturator foramen (inside out) is implemented with the same steps.
However, in the TOT surgery described above, a specialized insertion needle (for example a helical needle) is used and blindly inserted, and compared to conventional TVT, the distance the needle passes is short and is safe, but with an inexperienced surgeon, the insertion route cannot be reliably recognized, resulting in a risk of damaging the bladder, blood vessels, digestive tract or the like, causing serious complications.
Furthermore, pelvic organ prolapse is a separate disorder from which females suffer, which is similar to urinary incontinence. In this disorder, the pelvic organs, such as the uterus or bladder, which are being supported in a hammock shape by way of the pelvic floor muscle group, prolapse from the vagina due to weak pelvic floor muscles caused by aging or the like, which is so-called uterine prolapse or cystocele. Conventionally, as a repair method for pelvic organ prolapse, reinforcement colporrhaphy, wherein incisions were made in the vaginal wall and the prolapsed portion was shortened and stitched, was performed, but in recent years, as a substitute technique, TVM (Tension-free Vaginal Mesh) surgery for pelvic organ prolapse has been adopted, which make it possible to prevent the pelvic organs from prolapsing from the vagina by supporting the entire pelvic floor with polypropylene mesh in a hammock shape (see JP-2006-506104-A, for example).